Adjustable vane pump

ABSTRACT

An adjustable vane pump having a bowl-shaped hosing and having a rotor rotatably supported about a rotor axis and guiding at least one vane that is supported such that it can move in the radial direction. The housing includes a first thrust surface and a second thrust surface for the rotor, including the vane, which are transverse to the rotor axis. The second thrust surface is formed by a housing floor. The housing includes an adjustment housing, disposed between the thrust surfaces, which encloses the rotor, including the vane, and can be displaced transverse to the rotor axis, and includes a primary housing that encloses the adjustment housing. A suction intake and a pressure outlet are provided in the housing floor, and the axial extension of the primary housing is greater than the axial extension of the adjustment housing, the rotor, and/or the at least one vane.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims priority to German Patent Application No. DE 10 2014 203 193.1, filed on Feb. 21, 2014.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates, generally, to pumps and, more specifically, to an adjustable vane pump.

2. Description of the Related Art

Adjustable vane pumps known in the related rt, such as an oil pressure pump, may include a bowl-shaped housing with a rotor supported in the housing such that the rotor can rotate about an axis of rotation. The rotor guides at least one vane supported on the rotor such that the vane can move in the axial direction. The housing has a first (upper) thrust surface running at a right angle to the rotor axis, and a second (lower) thrust surface running parallel thereto, for the rotor and vanes. The second thrust surface is formed by a housing floor. The housing includes: an adjustment housing, disposed between the thrust surfaces, enclosing the rotor and vanes, and which is adjustable transverse to the rotor axis; and a primary housing encompassing the adjustment housing.

Vane pumps of this type are used in motor vehicles, in the form of oil pressure pumps for motor oil or transmission fluid. The pumps, or their rotors, respectively, are powered by a motor, in particular by a camshaft of an internal combustion engine. Vane pumps typically include a crescent-shaped pressure compartment which is subdivided into pressure chambers by at least one vane. By turning the rotor, which is disposed eccentrically to the interior walls of the adjustment housing, a pressure difference between a suction intake and a pressure outlet can be created.

Vane pumps of this type are adjustable (or, variable); by displacing the adjustment housing, the size of the crescent-shaped pressure compartment can be adjusted and, as a result, the pump characteristic is also modified. Depending on specific application requirements, the performance of the vane pump can therefore also be adjusted.

With vane pumps of this type, the vane pump needs to be as tightly sealed as possible. Specifically, the primary housing needs to rest against the thrust surface in a sealed manner. In addition, the adjustment housing and the rotor need to be able to be moved in a functionally stable manner between the thrust surfaces. Moreover, because of application requirements and installation orientations of vane pumps, it is desirable that the suction intake and the pressure outlet can be attached to the vane pump from the same direction.

SUMMARY OF THE INVENTION

The present invention overcomes the disadvantages in the related art an adjustable vane pump having a bowl-shaped housing and a rotor rotatably supported about a rotor axis. The rotor guides at least one vane supported so as to move radially. The housing includes a first thrust surface and a second thrust surface for the rotor and vane, which are transverse to the rotor axis. The second thrust surface is formed by a housing floor. The housing includes an adjustment housing, disposed between the thrust surfaces, which encloses the rotor and vane, and which can be displaced transverse to the rotor axis. The housing also includes a primary housing that encloses the adjustment housing. The axial extension of the primary housing is greater than the axial extension of the adjustment housing, the rotor, and/or the vane. A suction intake and a pressure outlet are provided in the housing floor. The suction intake is encircled by a gasket provided on the housing floor such that an upper side of a provided channel, facing the housing floor, is connectable in a sealed manner to the suction intake, under tension.

A vane pump of this type provides that a suction intake and a pressure outlet are provided in the floor of the housing, wherein the axial extension of the primary housing is greater than the axial extension of the adjustment housing, the rotor, and/or the vane. Because the axial extension of the primary housing being at least slightly greater than the axial extension of the moving components present in the housing, it can be ensured that the two end surfaces of the primary housing come to rest securely against the two thrust surfaces, and that the moving components (for example, the adjustment housing, the rotor, and the vane) can be moved freely in the housing, even if the second (lower) thrust surface is pushed toward the first (upper) thrust surface by vacuum present in the region of the suction intake in the housing. Due to the installation position, the housing floor can be pushed toward the first thrust surface. As a result, a defined gap axially between the thrust surfaces and the end surfaces of the moving components facing the thrust surfaces can be provided so as to avoid clamping or wedging of these components between the two thrust surfaces. The axial extension is the extension of the respective components, in the axial direction between the two thrust surfaces.

Because of the greater axial extension of the primary housing than the other moving components in the housing, the suction intake and the pressure outlet may be provided in the housing floor. Thus, because of the design of the pump, the moving parts inside the housing cannot become clamped or wedged in an undesired way, even though the suction intake is provided in the housing floor.

Thus, both the pressure outlet and the suction intake can be introduced in the axial direction, through the housing floor (in particular from below) to the pump, wherein it is thus ensured that the pump will function in a stable way.

Furthermore, it is advantageous if the axial extension of the adjustment housing, the rotor, and the vane (thus, the extension of the components) is identical in the axial direction between the two thrust surfaces.

Furthermore, it is advantageous if the axial extension of the primary housing is greater than the axial extension of the adjustment housing, the rotor, and/or the vane, in the range of 1/1,000 mm-1/100 mm. In particular, in the range of 5/1,000 mm-5/100 mm. As a result, a defined axial gap can be established between the end surfaces of the adjustment housing, the rotor, the vane, and the two thrust surfaces.

Advantageously, the adjustment housing, the rotor, and the vane can be made from the same material, such as metal (in particular, steel). In this way, it is ensured that the thermal expansion of the adjustment housing, the rotor, and the vane is substantially identical.

In one embodiment, the first (upper) thrust surface can be formed by a housing cover, which, in turn, can be connected in a fixed manner to the primary housing.

In order to separate the suction intake and the pressure outlet, it is advantageous if a gasket is provided on the housing floor, on the side facing the rotor, which encompasses the suction intake and/or the pressure outlet. In this way, a separation of the intake and outlet can be provided.

The rotor is advantageously powered by a rotor shaft which penetrates the housing floor and is rotatably supported by a thrust ring on a bearing bushing provided on the housing floor, wherein the gasket then also encompasses the region of the bearing bushing adjacent to the suction intake. The bearing bushing can also be designed as a single piece, incorporated in the housing floor. Advantageously, the region of the bearing bushing is allocated to the suction region.

Furthermore, it is advantageous if, in addition to the primary housing, an outer housing is provided, encompassing the primary housing in the radial direction, wherein the outer housing preferably extends above the primary housing in the axial direction, and the housing floor is enclosed by the outer housing, at least in sections. In this way, an encapsulation of the primary housing and the base can be provided. In addition, it is conceivable that other sealing elements can be provided between the outer housing and the primary housing and/or the housing floor for further sealing purposes (for example, encompassing sealing rings). It is thus further conceivable that the housing floor may include an encompassing seal on its radial outer side, for a sealing attachment to one of the intakes for the vane pump. Accordingly, the outer housing may also include seals of this type.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features, and advantages of the present invention will be readily appreciated as the same becomes better understood after reading the subsequent description taken in connection with the accompanying drawing wherein:

FIG. 1 is bottom side plan view of a vane pump.

FIG. 2 is a sectional view of the pump taken along line II-II of FIG. 1.

FIG. 3 is a sectional view of the pump taken along line III-III of FIG. 1.

FIG. 4 is a cut view of the pump taken along line IV-IV of FIG. 3.

FIG. 5 is an alternate sectional view of the pump of FIG. 2 shown in an installation situation.

DETAILED DESCRIPTION OF THE INVENTION

With reference now to the drawing(s), an adjustable vane pump 10 is shown in the figures, which, as depicted by the cuts according to FIGS. 2 and 3, includes a multi-part housing 12 which encloses a pump compartment 14. A rotor 18, disposed such that it can rotate about a rotor axis 16, is provided in the pump compartment 14. In order to rotate the rotor 18, the rotor 18 is rotatably coupled to a rotor shaft 20. The rotor 18 moves vanes 22 that are supported in the rotor 18 such that the vanes 22 can be displaced in the radial direction (see FIG. 4).

In the axial direction, thus in the direction of the rotor axis 16, the pump compartment 14 is bordered by a first, upper thrust surface 24 and by a second and lower thrust surface 26, parallel thereto. The upper thrust surface 24 is formed by a housing cover 28 thereby; the lower thrust surface 26 is formed by a housing floor 30.

In the radial direction, thus transverse to the rotor axis 16, the pump compartment 14 is bordered by an adjustment housing 32. As shown in FIG. 4, the radially outward lying vane tips of the vane 22 lie against the internal wall of the adjustment housing 32. The rotor 18 is disposed eccentrically in the pump compartment 14. Between the rotor 18 and the internal wall of the adjustment housing 32 there is a crescent-shaped pressure compartment 42, which is subdivided into pressure chambers by the single vane 22. When the rotor 18 is rotated, a pressure difference is obtained in the crescent-shaped pressure compartment 42.

The adjustment housing 32 can, as such, as is likewise shown in FIG. 4, be adjusted in the direction of the arrow 34, transverse to the rotor axis 16. The adjustment housing 32 is pushed into a home position by adjustment springs 36. The adjustment housing 32 borders two pressure chambers 38 and 40, lying radially outward (see FIG. 4). The pressurizing of the pressure chamber 40 via a pressurizing medium moves the adjustment housing 32 toward the left as shown in FIG. 4, counter to the force of the adjustment springs 36. By moving the adjustment housing 32 in the direction of the arrow 34, the eccentric position of the rotor 18 inside the adjustment housing 32 is altered, and thus the size of the crescent-shaped pressure compartment 42; accordingly, the pump capacity of the pump is altered.

The adjustment housing 32 is enclosed radially by a primary housing 44. As shown in FIGS. 2 and 3, the primary housing 44, the adjustment housing 32, and the rotor 18, with the vanes 22, are located axially between the two thrust surfaces 24 and 26. Furthermore, as shown in FIG. 2, a suction intake 46 and a pressure outlet 48, spatially separated from the suction intake 46, are provided in the housing floor 30. The pressure intake 46 and the pressure outlet 48 extend thereby in the axial direction, through the housing floor 30 into the pressure compartment 42. When the rotor 18 is rotated, the fluid (such as transmission fluid or motor oil) is thus suctioned off via the suction intake 48, and conveyed out of the pump 10 via the pressure outlet 48.

In order to ensure a functionally stable rotation of the rotor 18, including the vanes 22 in the pump compartment 14, and in order to additionally enable a functionally stable displacement of the adjustment housing 32, the axial extension A of the primary housing 44 is slightly greater than the axial extension of the adjustment housing 32 as well as the rotor 18, including the vanes 22. Advantageously, the axial extension of the primary housing in the region between the two thrust surfaces 24 and 26 is greater than the axial extension of the adjustment housing 32 and the rotor 18, together with the vanes 22, in the range of 5/1,000 mm-5/100 mm. In this way, it can be obtained that, in particular during operation of the pump, enough play in the axial direction is present between the moving parts in the pump, thus the adjustment housing 32, and the rotor 18, including the vanes 22, and the thrust surfaces 24, 26. In this regard, the pump 10 can thus be operated in an operationally stable manner.

Advantageously, the axial extension between the thrust surfaces 24, 26 of the adjustment housing 32, the rotor 18 and the vanes 22 is of the same size; thus, the components are of identical height. The specified components may made of the same or a similar material, such that their thermal expansion behavior is the same to the greatest extent possible.

For the radial guidance of the vanes 22, two inner races 72 are provided encircling the rotor shaft 20, wherein one inner race 72 rests against the upper thrust surface 24 and one inner race 72 rests against the lower thrust surface 26.

As shown in FIG. 1, the suction intake 46 is encompassed by an encircling gasket 50 disposed on the housing floor 30. The gasket 50 is inserted thereby (see FIGS. 2 and 3) in sections in the axial direction, and in particular, halfway, in the housing floor 30. The gasket 50 thus separates the region of the pressure outlet 48 from the region of the suction intake 46. Nevertheless, the suction intake 46 and the pressure outlet 48 are both provided, adjacent to one another, on the bottom of the pump 10.

As shown in FIGS. 3 and 4, the primary housing 44 is encompassed by an external housing 52. The external housing 52 extends in the axial direction beyond the primary housing 44, such that the housing floor 30 is covered approximately halfway by the external housing 52. The housing floor 30 exhibits a shoulder 54, which rises in the radial direction, which is substantially flush with the external surface of the outer housing 52. An encompassing sealing ring 56 is provided in the region of the shoulder 54. In order to seal the external housing 52 from the housing floor 30, an encompassing sealing ring 58 is likewise provided on the housing floor 30. In order to dispose the primary housing 32 in an exact position on the housing floor 30, alignment pins 60 are provided, extending in the axial direction. The primary housing 52 can be flange-mounted on the housing cover 28 by connecting screws 62. As is likewise shown in FIGS. 2 and 3, the rotor shaft 20 passes through the housing cover 28. The rotor shaft 20 can be made to rotate via its free end 64. The rotor shaft 20 is also rotationally coupled to the rotor 18. The rotor shaft 20 is, moreover, rotationally supported via a thrust ring 68, attached to the rotor shaft 20 via a screw 66, and rotationally supported on the housing floor 30 via a bearing bushing 60 provided on the housing floor 30.

In FIG. 5, the pump 10 depicted in FIGS. 1-4 is shown in an installation situation. The external housing 52 that is adjoined to the shoulder 54 on the housing floor in a flush manner is inserted in a cylindrical accommodation 74. A seal between the housing floor 30 and the accommodation 74 is created by the sealing ring 56. A channel 76 is provided in the region of the floor of the accommodation 74, which is open toward the floor 30, bordered by an encompassing wall 78. The upper side of the channel 76, facing the housing floor 30, rests tightly against the gasket 50 thereby. In this way, the channel 76 is connected in a sealed manner to the suction intake 46 for the pump 10, under tension. The tensioning can, for example, be provided via the seal 50 or via a spring element that can be provided. The pressure outlet 48 provided in the housing floor 30 opens into a pressure channel 80, which runs along the outer side of the wall 78 of the channel 76. The medium conveyed by the pump 10 can be supplied to the respective load via the pressure channel 80. As shown FIG. 5, with an assembly of this type the suction side, as well as the pressure side, of the pump 10 can lead to the pump axially from below. The axial extension of the external housing 52 is selected thereby such that in the installed state, a slight axial gap is provided between the shoulder 54 and the end surface of the external housing 52 facing the shoulder 54. In this way, the two end surfaces of the primary housing 44 facing one another come to rest in a sealed manner against the two thrust surfaces 24, 26.

With an increase in the pump pressure, the pressure in the pressure channel 80 also increases. As shown in FIG. 1, the crosshatched area of the housing floor 30 is pressurized, when the pressure in the pressure channel 80 is increased. This leads to a decrease of the axial gap, whereby axial gap compensation is provided. As shown in FIG. 5, the housing floor 30 is then pressed more strongly against the primary housing 44 and the primary housing is pressed more strongly against the housing cover 28. Nevertheless, due to the greater axial extension of the primary housing 44 than of the adjustment housing 32, the rotor 18 and the vane 22, no clamping of these moving parts occurs inside the housing 12. The pump 10 functions in a functionally stable manner.

The invention has been described in an illustrative manner. It is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described. 

What is claimed is:
 1. An adjustable vane pump comprising: a bowl-shaped hosing and a rotor rotatably supported about a rotor axis and guiding at least one vane supported such that the vane can move in the radial direction, wherein the housing includes a first thrust surface and a second thrust surface for the rotor, including the vane, which are transverse to the rotor axis, wherein the second thrust surface is formed by a housing floor, and wherein the housing includes an adjustment housing, disposed between the thrust surfaces, which encloses the rotor, including the vane, and can be displaced transverse to the rotor axis, and wherein the housing includes a primary housing that encloses the adjustment housing, and wherein the axial extension of the primary housing is greater than the axial extension of the adjustment housing, the rotor, and/or the at least one vane, and wherein a suction intake and a pressure outlet are provide in the housing floor, wherein the suction intake is encircled by a gasket provided on the housing floor such that an upper side of a provided channel, facing the housing floor, is connectable in a sealed manner to the suction intake, under tension.
 2. The vane pump as set forth in claim 1, wherein the axial extension of the adjustment housing, the rotor and the vane is of equal size.
 3. The vane pump as set forth in claim 1, wherein the axial extension of the primary housing is greater than the axial extension of the adjustment housing, the rotor, and/or the vane in the range of 0.001 mm-0.01 mm.
 4. The vane pump as set forth in claim 1, wherein the adjustment housing, the rotor, and the vane are made of the same material and/or exhibit the same thermal expansion behavior.
 5. The vane pump as set forth in claim 1, wherein the first thrust surface is formed by a housing cover.
 6. (canceled)
 7. The vane pump as set forth in claim 1, further including a rotor shaft that drives the rotor, passes through the housing floor, and is rotatably supported via a thrust ring on a bearing bushing provided on the housing floor; and wherein the gasket also encloses the region of the bearing bushing.
 8. The vane pump as set forth in claim 1, further including an external housing enclosing the primary housing, wherein the external housing extends beyond the primary housing in the axial direction, and the housing floor, at least in sections, is enclosed by the external housing.
 9. The vane pump as set forth in claim 1, wherein the housing floor has an encircling seal on its radial outer side, for creating a sealing connection to an accommodation that receives the vane pump.
 10. The vane pump as set forth in claim 1, wherein the axial extension of the primary housing is greater than the axial extension of the adjustment housing, the rotor, and/or the vane in the range of 0.005 mm-0.05 mm.
 11. The vane pump as set forth in claim 1, wherein the vane pump is disposed in an accommodation that receives the vane pump.
 12. A vane pump disposed in an accommodation and comprising: a bowl-shaped hosing and a rotor rotatably supported about a rotor axis and guiding at least one vane supported such that the vane can move in the radial direction, wherein the housing includes a first thrust surface and a second thrust surface for the rotor, including the vane, which are transverse to the rotor axis, wherein the second thrust surface is formed by a housing floor, and wherein the housing includes an adjustment housing, disposed between the thrust surfaces, which encloses the rotor, including the vane, and can be displaced transverse to the rotor axis, and wherein the housing includes a primary housing that encloses the adjustment housing, and wherein a suction intake and a pressure outlet are provided in the housing floor, wherein the suction intake is connected to a channel, wherein the pressure outlet opens into a pressure channel, which runs along the outer side of the wall of the channel, and wherein with an increase in the pump pressure, the pressure in the pressure channel increases, thereby pressing the housing floor more strongly against the primary housing and pressing the primary housing more strongly against the housing cover. 